Means for vaporizing fuel for internal-combustion engines



April 29 1924. 1,491,950

W. M. HARRISON MEANS FOR VAPORIZING FUEL FOR INTERNAL COMBUSTION [ENGINES Filed Jan. 5; 1923 //V VE N 70 Patented Apr. 29, 1924.

uurrso STATES PATENT orncs.

WILFBID IATTHEW HABBISCN, OF CHRHUNT, IILNGLAB'I'IIJ.

MEANS FOR VAPORIZING FUEL FOR INTERNAL-COMBUSTION ENGINES.

Application filed January 5, 1928. Serial No. 610,878.

interposed between, say a carburetter and the induction pipe of the engine, so that the heating element enters the duct conveying the explosive mixture to the cylinder or cylinders. Many proposals of this general kind are known but as far as I am aware none satisfactorily meets the various requirements of modern practice which include a minimum of obstruction to the flow of mix ture, a resistance element which isso protected that the mixture cannot come in contact therewith even in case of accident, whereby fire risk is avoided, and as effective a heating of the wall of the duct as possible in order to prevent condensation in the duct and on the wall thereof of vapour after it has formed.

All these features in combination are present in electrical heating means according to the present invention which comprises a length of resistance material, such as ni-- chrome wire or strip,'covered with insulation material, as for instance asbestos and enclosed within a metal casing.

The composite electrical heating element thus constituted is caused to assume a crenellated or a zigzag loop shape and is bent as a whole to a circular shape and fixed to a flange-like carrier. the projecting portions, of the heating element remote fromthe flange carrier, which-resemble fingers, being bent outwardly so that when the carrier is placed in osition with the heating device 7 extending into the induction pipe or duct of an engine, the fingers will bear snuglfy 1 against the inner surface of the pipe at d ferent' pipe w on the heating element is switched, into circuit with a battery, the said heating element at the same time offering practically no obstruction to vapour flowing through and past it.

The casing may be produced by electrical j plarts therof, and effectually heat the deposition of metal upon or over the insulated length of insulated resistance material, suitably repared for the purpose, or, as is preferre ,by coverin the insulated length of resistance materia with a copper tube drawn out over the length of insulated resistance material until it forms almost or quite a tight fit therewith. The heating element thus constituted is then bent into the form mentioned for insertion into the induction pipe of an engine, or into the carburettor, or into both thereof.

The invention is capable of being variously carried into effect and the details of construction modified without departin from the scope of the invention but it suffice to describe two specific forms with reference to the accompanying drawings, whereof Fig. 1 is a art sectional elevation of a portion of one orm of device as it appears at an intermediate stage in the manufacture thereof. Fig. 2 is a plan of the device complete and Fig. 3 is a section on the line 33 Fig. 2. Fig. 4 is a perspective view of the second form of device which is of simplified construction and Fig. 5 is a secter, or into both thereof.

In each case a convenient form of heater is obtainable by taking a length a of resistance material such as nichrome wireor strip and bending or folding the same so that in outline it resembles an embattlement. The heating element thus constituted is housed in a suitable metal casing; In the first example the casin b has a series of pockets 6' extending para lelto one another laterally from a straight region c adapted to be bent I circularly so that when inserted into the induction pipe or fuel .duct the pockets extend parallel to the axis of such pipe or duct. The casing referred to may be carried by a flange member d of insulating material in which holes e are or can be made to suit those of existin carburetter flanges, the said insulating ange being provided with terminals f for connection to the electrical source of Sn ply. It is preferred that after the casing as been bent the pockets b should have a slight diver nce as shown in Fig. 3 necessitating them ein to a certain extent sprung before they can inserted in the pi e or duct, their natural elasticity therea er causing them to snu 1y 1' against the metal of the pipe or uct, In

this way danger'of overheating is avoided in any suitable way and confines both the heating element a and a surrounding or envelo ing la er 9 of insulating material whic may be asbestos impregnated or not with sodium silicate for example. As it is or may be desirable that the casing should be gas tight, the same may be com leted or entirely produced by the electrica de s1- tion of metal upon or over the insu ated heating element. The casing may be fa stened to the insulating flange member (1 in any convenient way such as by form ng or providing the former with a ledge or run It, saw cut at intervals so that when the casing is bent it forms an external peripheral n argin which can sprung into position within a circumferential groove in the flan member as shown in Fig. 3, the length of e casing being selected to permit of this being done. The ends of the heating element a may ass from the casing in any suitable way, ing reinforced if desired in order to obtain mechanical strength and prevent overheating. I

The second form of device shown in Figs. 4 and 5 and which may be preferred on account of its simple construction is produced by enclosing an insulated nichrome or like resistance wire it within a-tubular metal casing i and then bending the same to the shape shown. The ends of the said casin areinserted into holes in the insulating ange d so that it is supported therefrom with embattlement like loops projecting in a manner which enables them to be inserted in and make contact with the walls of the duct' as already referred to. The heating elements a may advantageously be encased by employing a copper or like tube of appropriately large diameter to permit of'the insulated wirebeing passed therethrough and then by a drawingoperntionto stretch and gradually diminish the diameter of the tube until it envelops the insulated wire and makes intimate contact therewith.

If desired and as shown ii -Fig. 3 a wire gauze or perforated member is may be employed which will act to atomize the mixture, to deflect a large proportion of the mixture into contact with the heater, to dis seminate heat to the mixture by conduction and to prevent flame from any cause firing back to the carburetter.

Said device 7: may appropriately be of truncated conical form with a disc at at the smaller end, and arranged so that the disc is in advance of the base considering the engine cylinder; as exemplified the device k is formed with a margin. or rim n to enable it to be clam ped to the insulating flangefgl by the ledge or rim hof the casing be,

As willbe obvious the heater according to the present invention will raisethe temperature within the pipe or fuel duct more ra idly than does an external heater and quicker startin will result but the heating means should left in circuit for a greater len 11 of time after starting in order to thoroug ily heat the surroundings of the mixing chamber or it ma be found that there is an immediate fa ling off in power before the engine has been running long enough to supply its own heat to the mixture. In the case of the external heater this thorough warming requires to be effected before starting is attempted.

What I claim is z' 1. In an internal combustion engine, a

conduit and an electrical heater adapted to be inserted in said conduit, the heater comprising a length of resistance material, a covering of insulatin material and an enclosing casing of meta the casing'bcing subsequently bent to a circular form so as to gniformly engage the inner .wall of the con uit.

2. In an internal combustion engine, a conduit and an electrical heater adapted to be inserted in said conduit, the heater comprising a length of resistance material a covering of insulating material and an enclosing casin of metal, the casing being subsequently nt into a zig-zag and circular form so that the zigzag rtions uniformly enga the inner wall of t e conduit.

3. n a fuel heater for the induction pi of an internal combustion engineor Iii: conduit, a length of insulated resistance wire and a metallic casing therefor comprising a tube which by a rocess of drawing is stretched over the insulated wire so as .to

E285 tightly upon the latter, the said casing duit, comprising a length 0 insulated resist ance wire over which is drawn a tubular metal casing, the said casing being bent into a zig-zag formation and the whole thereafter bent into a form such that the several loops are each adapted to make'contact with part of the internal wall of the conduit, a flange member adapted to be secured to the conduit to form a continuation thereof and to support-the casing in the conduit, and terminals upon said flange member connected to the resistance wire and by means of which an electric current can be conducted thereto substantially as described.

Signed at London, England, this 20th day of December, 1922.

- WILFRID MATTHEW HARRISON. 

